What do the following two equations represent? $x+y = -3$ $-4x-4y = 12$
Explanation: Putting the first equation in $y = mx + b$ form gives: $x+y = -3$ $y = -x-3$ Putting the second equation in $y = mx + b$ form gives: $-4x-4y = 12$ $-4y = 4x+12$ $y = -1x - 3$ The above equations turn into the same equation, so they represent equal lines.